1. Volume 18, Issue 7, Pages 920-927 (July 2011)
Cholesterol Secosterol Aldehydes Induce Amyloidogenesis and Dysfunction of Wild- Type Tumor Protein p53 
Jorge Nieva, Byeong-Doo Song, Joseph K. Rogel, David Kujawara, Lawrence Altobel, Alicia Izharrudin, Grant E. Boldt, Rajesh K. Grover, Anita D. Wentworth, Paul Wentworth 
Chemistry & Biology 
Volume 18, Issue 7, Pages (July 2011)
DOI: /j.chembiol
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2. Figure 1 A Model for Lipid-Aldehyde Initiated p53 Inactivation
Scheme showing the concept of how membrane lipids, upon oxidation by reactive oxygen species (ROS), generate lipid-derived aldehydes such as KA, ALD, HNE, and HHE, which then adduct reversibly to lysine residues of cellular proteins, such as p53, which can then lead to misfolding/aggregation and dysfunction. The protein shown is a surface rendering of the p53 tetramerization domain (PDB reference 1tub), with surface lysines highlighted in blue.
Chemistry & Biology  , DOI: ( /j.chembiol )
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3. Figure 2
Lipid Aldehydes KA and ALD, but Not HNE and HHE, Induce Amyloidogenesis and Dysfunction of Recombinant His6-p53
(A) Graph of ThT fluorescence versus time during quiescent incubation of His6-p53 (0.8 mg/ml) in PBS (pH 7.4) with ethanol (0.1% v/v) cosolvent in the presence of KA, ALD, HNE, or HHE (each at 100 μM). Data are reported as the mean fluorescence emission (excitation, 440 nm; emission, 485 nm) of duplicate experiments.
(B) Graph of KA concentration-dependent (0–200 μM) quiescent aggregation of His6-p53 (0.8 mg/ml) in PBS (pH 7.4) with ethanol (0.1% v/v) cosolvent, as measured by ThT fluorescence. Data are reported as the mean fluorescence (excitation, 440 nm; emission, 485 nm) of duplicate experiments. Data are fitted to a third-order polynomial using GraphPad Prism 4 for Macintosh.
(C) Optical microscope images (100×) obtained under normal (upper) and cross-polarized (lower) light of aggregates generated by incubation of His6-p53 (0.8 mg/ml) with KA (25 μM) for 5 hr, followed by centrifugation and staining with Congo red (100 μM).
(D) FTIR spectra at times (0 min [yellow], 300 min [blue], 800 min [green], and 1200 min [(red]) during the quiescent aggregation of His6-p53 (0.5 mg/ml) in D2O with KA (100 μM).
(E) Graph of functional p53 (as a percentage of t = 0) versus time during the quiescent aggregation of His6-p53 (0.8 mg/ml) in the presence of ALD (50 μM) or VEH (ethanol 0.1% v/v). Data are mean ± SEM of at least duplicate determinations. Data for VEH are fitted to a linear regression analysis (r2 = 0.992); data for ALD are fitted to a single-phase exponential decay using GraphPad Prism 4.
(F) Graph of functional p53 (in ng/ml) versus ALD during a 2 hr quiescent aggregation of His6-p53 (0.8 mg/ml) in the presence of ALD (0–80 μM). Data are reported as the mean ± SEM of at least duplicate determinations. Data are fitted to a single-phase exponential decay using GraphPad Prism 4.
See also Figure S1.
Chemistry & Biology  , DOI: ( /j.chembiol )
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4. Figure 3
Lipid Aldehydes Affect Wild-Type p53 DNA Binding and p21 Activation in Cells
(A) Bar chart representing level of DNA binding nuclear p53 extracted from A-427 cells incubated at 37°C for 24 hr with VEH (0.1% ethanol), HNE, HHE, KA, or ALD (each at 40 μM) after receiving a dose of γ-radiation (5000 cGy). After the incubation, nuclear extracts were taken, and total protein (BCA), p53 (western blot), and functional p53 (ELISA) were measured. Data are reported as the mean ± SEM of triplicate determinations. Data were analyzed using a Student's two-tail t test and were considered significantly different from VEH (∗) if p < 0.05.
(B) Upper view is a western blot analysis of p53 and p21 in nuclear protein extracts from A-427 cells before (−) and after (+) receiving γ-radiation (5000 cGy). Lower view is a western blot analysis of p53 and p21 in nuclear protein extracts from A-427 cells. Cells were incubated at 37°C for 24 hr with ALD (0–30 μM) after receiving a dose of γ-radiation (5000 cGy). After the incubation, nuclear extracts were taken, and total protein (BCA), p53, and p21 (western blot) were measured.
(C) Agarose gel analysis of p21 PCR DNA derived from p53 immunoprecipitation (IP) of A-427 genomic DNA. Lane 1 shows 100 bp ladder; lane 2, A-427 genomic DNA with p53 IP (after irradiation); lane 3, A-427 genomic DNA with p53 IP (after irradiation and incubated with VEH for 20 hr); and lane 4, A-427 genomic DNA with p53 IP (after irradiation, ALD, 30 μM for 20 hr).
Chemistry & Biology  , DOI: ( /j.chembiol )
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